Mostefai came from the town of Courcouronnes, 25km (15 miles) south of Paris. He had been identified by the security services as having been radicalised but had never been implicated in a counter-terrorism investigation.

Investigators are trying to find out whether he travelled to Syria in 2014, judicial sources told AFP.

French police have taken Mostefai's father and brother into custody and searched their homes.

Mostefai's older brother attended a police station voluntarily.

"It's crazy, insane. I was in Paris myself last night, I saw what a mess it was," he told AFP before being placed in custody.

He said he had not had contact with his younger brother for several years.

Media captionPeople could be seen escaping from the Bataclan concert hall shortly after a series of explosions

Mr Molins also said the arrests of three men in Belgium on Saturday were linked to the attacks.

Belgian Prime Minister Charles Michel said investigators were trying to establish whether one of the suspects picked up near Brussels might have been in Paris on Friday evening.

Speaking in Paris on Saturday evening, Mr Molins told reporters: "We can say at this stage of the investigation there were probably three co-ordinated teams of terrorists behind this barbaric act."

Mr Molins said all seven militants had used Kalashnikov assault rifles and the same type of explosive vests.

Media captionProsecutor Francois Molins: "We have to find out where they came from... and how they were financed"

The investigation

Mr Molins also gave details about the state of the investigation, which he said was at a very early stage.

He said police were focusing on two vehicles. One is a black Seat used by gunmen at two of the attacks, and still untraced.

The other is a black Volkswagen Polo with Belgian registration plates found at the concert venue that was targeted.

He said this had been rented by a Frenchman living in Belgium.

He was identified while driving another vehicle in a spot check by police on Saturday morning as he crossed into Belgium with two passengers.

The BBC's Hugh Schofield in Paris says investigators are working on the theory that these three may be another team of attackers who managed to flee the scene.

The Greek authorities say two people under investigation by the French police had registered in Greece as Syrian refugees. A Syrian passport was found near the body of one the attackers at the Stade de France.

An Egyptian passport has also been linked to the attacks.

How the attacks unfolded

Media captionHow the attacks in Paris unfolded on 13 November 2015

French President Francois Hollande imposed a state of emergency after the worst peacetime attack in France since World War Two. It is also the deadliest in Europe since the 2004 Madrid bombings.

The violence began soon after 21:00 (20:00 GMT) as people were enjoying a Friday night out in the French capital.

Gunmen opened fire on Le Carillon bar and Le Petit Cambodge (Little Cambodia) restaurant, near the Place de la Republique in the 10th arrondissement (district), killing 15 people.

The 1,500-seat Bataclan concert hall in the 11th arrondissement suffered the worst of Friday night's attacks. Gunmen opened fire on a sell-out gig by US rock group Eagles of Death Metal, killing 89 people.

"At first we thought it was part of the show but we quickly understood," Pierre Janaszak, a radio presenter, told AFP news agency.

He said the gunmen took 20 hostages, and he heard one of them tell their captives: "It's Hollande's fault, he should not have intervened in Syria."

Media captionA witness to the explosions at the Stade de France says he was saved by his mobile phone

Within an hour, security forces had stormed the concert hall and all three attackers there were dead.

Islamic State released a statement on Saturday saying "eight brothers wearing explosive belts and carrying assault rifles" had carried out the attacks on "carefully chosen" targets, and were a response to France's involvement in the air strikes on IS militants in Syria and Iraq.

Shortly before, President Hollande said France had been "attacked in a cowardly shameful and violent way".

"So France will be merciless in its response to the Daesh [Islamic State] militants," he said, vowing to "use all means within the law.. on every battleground here and abroad together with our allies".

Many officials buildings as well as Disneyland Paris have been closed, sports events have been cancelled and large gatherings have been banned for the next five days.

Image copyrightEPAImage caption
Paris is in mourning after Friday night's wave of attacks

Image copyrightAFPImage caption
French security forces are now on the highest state of alert

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